Body composition assessment measured via bioelectrical impedance analysis in euthyroid children with newly diagnosed Hashimoto's thyroiditis.

Objectives: The effects of thyroid hormones on body composition are well-known. We aimed to examine the body composition of children with and without Hashimoto's thyroiditis (HT) by bioelectrical impedance analysis (BIA) while they were still euthyroid.

Methods: Between the ages of 5 and 18, 53 girls and 12 boys in each group, 65 children with HT, and 65 healthy children were included in this study. The Tanita MC-780 MA model was used to evaluate body composition parameters. These are fat mass (FM), fat-free mass (FFM), muscle mass (MM), bone mass (BM), total body water (TBW), phase angle, the ratio of muscle mass to fat mass (MFR), basal metabolic rate (BMR), and sarcopenic index (SI). Weight, height, body mass index standard deviation scores (SDSs), and pubertal status were examined. Additionally, TSH, Free-T4, Free-T3, Anti-TPO, Anti-Tg, serum lipid levels, and thyroid volumes were compared.

Results: We observed that TBW (27.5 ± 7.5 kg vs. 24.8 ± 6.6 kg; p=0.029) and BMR (1,403 ± 253 kcal vs. 1,324 ± 200 kcal; p=0.049) were higher in the HT group. These differences are due to differences in age and muscle mass in the male group. The FM, FFM, MM, BM, MFR, SI, and phase angle scores did not differ between females with and without HT in euthyroid children by the BIA method.

Conclusions: There is no significant change in body composition in euthyroid females with HT at admission.